Material for the cementation or casehardening of iron and steel



Patented Apr. 29, 1924.

JQHH A. BAUMGARDNER, OE DETBOIT, MIOHKGMIT.

MATERIAL FOR THE CEMENTATION OR CASEHARDENING 0? E3016 Mm scram.

No Drawing.

To all whomit may concern:

Be it known that l, Jenn A. BAUM- GARDNER, a citizen of the United States, and resident of Detroit, county of Wayne, State 5 of Michigan, have made a new and useful Invention in a Material for the Cementation or Casehardening of Iron and Steel, which is fully set forthin the following description.

The most commonly used mixtures for this purpose consist of a carbonaceous material, such as charcoal, coke, charred leather, lampblack, etc., as a base, combined I with one or more of the carbonates of the i5 alkali or the alkaline earth metals as energizer. The theory of the 'carburizing action of such mixtures is that it is due to the action of carbon monoxide gas generated when they are heated to the carburizing 2Q temperature.

At the same time, it is generally conceded that hydrocarbon gases are energetic carburizing agents.

My invention consists in the use of an as acetate of the alkali or the alkaline earth metals as an energizer, which ener er will, according to my theory,in itsel perform the functions of the carbonates in the above mixtures and at the same'time supplement no this action by the formation of hydrocarbon gases.

For example, lltake wood charcoal and coke, either singly or combined, to which I add 5 to 10 percent by weight calcium $5 acetate, although I do not restrictmyself to these percentages. My theory is that on heating, this energizer decomposes into cal- Ell Application filed October 7, 1921. Serial Ito. scares;

cium carbonate and acetone which latter subsequently breaks down into hydrocar hon gases and other compounds. Thus it has a double action and l have found it to be more effective than calcium carbonate as an energlzer.

I admit that it has been suggested to use barium acetate as an energizer in connection with charcoal in case hardening. However, barium acetate decomposes at a relatively low temperature, very much lower than calcium acetate. The result is that acetone, on which i rely to break down and form the hydrocarbon gases, escapes before the case hardening temperature is reached. With calcium acetate, which decomposes at a very much higher temperature and with the other alkali and as alkaline earth metals, such as potassium acetate and sodium acetate, the decomposing point is even higher than with calcium acetate, and l find that the acetone, which breaks down into the hydrocarbon game, as rgemains for part or all the carhnrization s p.

Having thus fully set forth the nature of my invention, what I claim as new is,-

1. A cementation or casehardening mixas ture containing a carbonaceous material and calcium acetate. 4

2. A cementation, or case hardening mixture containing a carbonaceous material, and an acetate of the alkali or r. l ,e earth to metals having a decomposing temperatnre at least as high as calcium acetate.

In testimony whereof I aw my 50% A. BAUMGARDE'ER 

